Indications of key-update process during direct package-index updates found in Ubuntu

In a previous post, I indicated that repository-keys are apparently updated during package-index updates performed with a direct internet connection, but without providing any indication that the keys are being updated. (The keys are not updated when an update is performed via APT-offline, which explains the "cannot authenticate packages" warnings which appear when installing software after performing an update via APT-offline.)

However, I've since created an installation of regular Ubuntu (which I've realized is much better than I previously indicated, although I still think that the workspace-switching scheme is excessive), and performed a direct update on it via the terminal, and noticed indications that the keys were updated first. So, this confirms my suspicions that the keys are updated during direct package-index updates, but it still doesn't mean that every detail of the process was divulged.